package collection;
/*集合*/
import java.util.ArrayList;
import java.util.Collection;

public class CollectionDemo {
    public static void main(String[] args) {
        Collection c = new ArrayList();
        c.add(new Point(1,2));
        c.add(new Point(3,4));
        c.add(new Point(5,6));
        c.add(new Point(7,8));
        c.add(new Point(9,0));
        c.add(new Point(1,2));
        //[元素1.toString(),元素2.toString(),元素3.toString(),....]
        System.out.println(c);

        /*
        * boolean contains(Object o);
        * 判断当前集合是否包含给定元素o
        * 判断依据数据是给定元素是否与当前元素集合存在的equals()比较是否为true的情况
        * */
        Point p = new Point(1,2);
        boolean contains = c.contains(p);
        System.out.println("是否包含"+contains);
        /*
        * bolean remove(Object o):------一般都不接收bo0lean的结果
        * 从当前集合中删除与给定元素o的equals()比较为ture的元素
        * 若存在重复元素，则只删一次
        * */
        c.remove(p);
        System.out.println(c);


        //集合中存放的是元素的引用，和数组一样装的是地址
        Collection cc = new ArrayList();
        Point pp = new Point(1, 2);
        cc.add(pp);//add装的是地址
        System.out.println("pp"+pp);
        System.out.println("cc"+cc);

        pp.setX(100);
        System.out.println("pp"+pp);
        System.out.println("cc"+cc);

        Collection ccc = new ArrayList();
        ccc.add("123");
        ccc.add("234");
        ccc.add("吃饭");
        ccc.add("喝酒");
        System.out.println(ccc);
        System.out.println("size:"+ccc.size());
        System.out.println("是否为空集:"+ccc.isEmpty());

        c.clear();
        System.out.println("集合已清空");
        System.out.println(ccc);
        System.out.println("size:"+ccc.size());
        System.out.println("是否为空集:"+ccc.isEmpty());
    }
}
